On the skins page the tool-bars have a sliver/grey background. But when I have them installed I get a blue background on the tool-bars as you can see from the attached screen-shots.

The skins do not include the toolbar. Not sure why the Toolbar background changes but it happens with most of them. If you change the toolbar this will change/reset the background of the toolbar icons.
E.g. Default -> Default (large) -> Default